Abstract: The main aim of the paper is to confirm a thesis that Russian Orthodox Church supports the theory about an all-Russian nation which includes Russian, Belarusian and Ukrainian people. The all-Russian nation is a kind of civilizations nation with its East-Slavonic basis, part of so called Russian world. It is a spiritual and religious community. The theory of the all-Russian nation promotes geopolitical and geocultural Russian influence in the post-Soviet area, especially in Belarus and Ukraine. The official position of Russian Orthodox Church is that Russians, Belarusians and Ukrainians are a unique nation divided into three independent states but they constitute a single spiritual and religious community.